1. Field of the Invention
The invention falls into the field of actuators for automatically maneuvering opening leaves of a house or a building in general, of the door or window type. It also falls into the field of closing assemblies comprising, amongst other things, such actuators.
2. Brief Description of the Related Art
Some of these actuators comprise a geared electric motor assembly capable of transmitting a movement to an arm, which pushes or pulls on the opening leaf, depending on the direction in which the geared motor unit is rotating.
In such an actuator, the arm may consist of a chain driven by a sprocket, itself connected to the output shaft of the geared motor unit by means optionally of an angle transmission. This chain is made up of links which may nest inside one another in such a way as to stiffen the chain so that it can be bent in only one direction. Thus, the rigid chain is able to transfer a mechanical force in order to pull or to push the opening leaf. The chain is generally folded up in a casing, around a guiding support which is fixed in the casing. It slides with respect to this guide when set in motion.
To maneuver large or heavy opening leaves, DE U 91 05 454 discloses the use of a device combining two assemblies each comprising a drive member and a maneuvering chain. The two drive members are electronically coupled so that they operate precisely at the same time. The differences in chain lengths or lash in the driveline create difficulties in adjusting and installing such a device.
Another approach is to use a mechanical synchronizing mechanism as described in U.S. Pat. No. 1,333,595. This mechanism is intended for the control of several opening leaves simultaneously or of one opening leaf that is heavy or unusually large in size. A double mechanism involving chains and sprockets is then used, the chains being connected at one end to the opening leaf and at the other end to a common drive member which moves longitudinally with respect to the opening leaf. As the drive member moves in a first direction of opening, the chains are driven and folded along guiding supports, from the drive element toward the opening leaf, and push on the latter in order to open it. Conversely, when the drive member is moved in an opposite second direction of closing, the chains are driven and folded along the guiding supports toward the drive member and pull on the opening leaf in order to close it. The mechanical structure of the chains allows the chains to be folded along the guiding supports.
On the other hand, EP-A-0 777 028 describes a mechanism the structure of which improves compactness and esthetics. This mechanism is also suited to automatically actuating heavy opening leaves or to countering the effect of the wind on windows that exhibit extensive windage, and to actuating opening leaves positioned side by side. An electric drive device, chains, return sprockets and guides for the chains are contained in a substantially closed casing provided with openings in a common face through which the chains leave. The guides are formed of grooves cut into the mass of the casing and in which the chains slide over their entire length. This is expensive and causes a great deal of slack in the movement of the chains.